The invention relates to a case hinge comprising a hinge pin and a hollow cylinder for the detachable connection of a case top and a case bottom. The pin is provided with an all-round groove for forming a locking edge and the hollow cylinder is provided with a resilient detent, which is rotatably and axially detachably engaged with the groove when the pin is located in the hollow cylinder. Such hinges are frequently used on tool or instrument cases. As both the case top and case bottom can receive the case content, it is advantageous if both case parts can be separated from one another on inserting the tools or instruments. However, in order to prevent an unintentional unhinging, the hinge is secured with the aid of a resilient locking element. Only when the spring tension is overcome by an operator is it possible to separate the two hinge parts.
Particularly in the case of cases, which are intended to receive measuring and indicating instruments or computers, it is also desirable for the case top to assume a predetermined swivel angle to the case bottom in the swung-up condition. For example, the case bottom can contain control elements and the case top indicating or display elements, which the operator should have in his field of vision with minimum restriction or impediment.
For this purpose it has hitherto been necessary to fit supports, strips or chains for preventing the swinging of the case top over and beyond the predetermined swivel angle. However, these measures lead to the disadvantage that said parts also have to be housed in the case interior. However, as both the case dimensions and the equipment to be housed therein are in many cases standardized, necessarily storage space is lost. It is also unavoidable that the case walls have to be perforated for fixing said support means, which leads to additional sealing problems. In addition, such components make it impossible or at least very difficult to separate the two case parts.